ZNF521 enhances MLL-AF9-dependent hematopoietic stem cell transformation in acute myeloid leukemias by altering the gene expression landscape
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA750400 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Leukemias derived from the MLL-AF9 rearrangement rely on deranged transcriptional networks. ZNF521, a transcription co-factor implicated in the control of hematopoiesis, has been proposed to sustain leukemic transformation in collaboration with other oncogenes. We demonstrate here that ZNF521 mRNA levels correlate with specific genetic aberrations: in particular, the highest expression is observed in AMLs bearing MLL rearrangements, while the lowest is detected in AMLs with FLT3-ITD, NPM1 or CEBPα double mutations. In cord blood-derived CD34+ cells, enforced expression of ZNF521 provides a significant proliferative advantage, and acts synergistically when co-expressed with MLL-AF9 throughout the proliferation and expansion of leukemic progenitor cells. Transcriptome analysis of primary CD34+ cultures displayed subsets of genes upregulated by MLL-AF9 or ZNF521 single transgene overexpression as well as in MLL-AF9/ZNF521 combinations, either at early or late time points of an in vitro model of leukemogenesis. Silencing of ZNF521 in MLL-AF9+ THP-1 cell line coherently results in an impairment of growth and clonogenicity, recapitulating effects observed in primary cells. Taken together, these results underscore a role for ZNF521 in sustaining self-renewal of the AML immature compartment, most likely through the perturbation of the gene expression landscape which ultimately favors the expansion of MLL-AF9 transformed leukemic clones.
2022-03-24 | GSE181006 | GEO
Project description:The transcriptional activating and repressive functions performed by Trithorax and Polycomb group complexes, respectively, are critical for to maintain cellular fates in ontogeny and in cancer. Here we report that leukemias initiated by a Trithorax-related oncogene, MLL-AF9, depend upon the Polycomb Repressive Complex 2 (PRC2) to sustain a transformed cellular state. RNAi mediated suppression of PRC2 subunits is sufficient to inhibit proliferation of MLL-AF9 leukemias, with little impact on growth of non-transformed cells. This requirement is partly due to PRC2-mediated transcriptional repression of several anti-self-renewal regulators, including Cdkn2a. These results suggest that, unlike the classical antagonism generally observed between Polycomb and Trithorax group proteins during development, the activities of these two pathways can cooperate to promote myeloid neoplasia. In order to understand downstream targets of PRC2 complex in MLL-AF9 leukemia, we performed array in murine MLL-AF9/NrasG12D cell line under the condition that two subunits of PRC2(Eed and Suz12) were suppressed by using shRNAs.
2013-07-01 | E-GEOD-34183 | biostudies-arrayexpress
Project description:The MLL gene is a common target of chromosomal translocations found in human leukemia. MLL-fusion leukemias are consistently poor prognosis. One of the most common translocation partners is AF9 (a.k.a. MLLT3). MLL-AF9 recruits DOT1L, a histone 3 lysine 79 methyltransferase (H3K79me1/me2/me3), leading to aberrant gene transcription. We show that DOT1L has three AF9 binding sites, and present the NMR solution structure of a DOT1L-AF9 complex. We generated structure-guided point mutations with graded effects on recruitment of DOT1L to MLL-AF9. ChIP-Seq analyses of H3K79me2 and H3K79me3 show that graded reduction of the DOT1L interaction with MLL-AF9 results in selective losses in H3K79me2 and me3 marks at MLL-AF9 target genes. Furthermore, the degree of DOT1L recruitment defines the level of MLL-AF9 hematopoietic transformation.
2015-04-30 | GSE64365 | GEO
Project description:The transcriptional activating and repressive functions performed by Trithorax and Polycomb group complexes, respectively, are critical for to maintain cellular fates in ontogeny and in cancer. Here we report that leukemias initiated by a Trithorax-related oncogene, MLL-AF9, depend upon the Polycomb Repressive Complex 2 (PRC2) to sustain a transformed cellular state. RNAi mediated suppression of PRC2 subunits is sufficient to inhibit proliferation of MLL-AF9 leukemias, with little impact on growth of non-transformed cells. This requirement is partly due to PRC2-mediated transcriptional repression of several anti-self-renewal regulators, including Cdkn2a. These results suggest that, unlike the classical antagonism generally observed between Polycomb and Trithorax group proteins during development, the activities of these two pathways can cooperate to promote myeloid neoplasia.
2013-07-01 | GSE34183 | GEO
Project description:The MLL gene is a common target of chromosomal translocations found in human leukemia. MLL-fusion leukemias are consistently poor prognosis. One of the most common translocation partners is AF9 (a.k.a. MLLT3). MLL-AF9 recruits DOT1L, a histone 3 lysine 79 methyltransferase (H3K79me1/me2/me3), leading to aberrant gene transcription. We show that DOT1L has three AF9 binding sites, and present the NMR solution structure of a DOT1L-AF9 complex. We generated structure-guided point mutations with graded effects on recruitment of DOT1L to MLL-AF9. ChIP-Seq analyses of H3K79me2 and H3K79me3 show that graded reduction of the DOT1L interaction with MLL-AF9 results in selective losses in H3K79me2 and me3 marks at MLL-AF9 target genes. Furthermore, the degree of DOT1L recruitment defines the level of MLL-AF9 hematopoietic transformation. Hematopoietic progenitor cells isolated from mouse bone marrow were transduced with retrovirus expressing either wildtype MLL-AF9 (WT), mutants, MLL-AF9 (D544R) and MLL-AF9 (D546R). ChIP-Seq analyses were performed on these wildtype and mutant cells using H3K79me2 and H3K79me3 antibodies. 3 samples corresponding to ChIP-Seq with H3K79me2 antibody: 1) MLL-AF9 (WT) 2) MLL-AF9 (D544R) 3) MLL-AF9 (D546R) 3 Samples Corresponding to ChIP-Seq with H3K79me3 antibody: 4) MLL-AF9 (WT) 5) MLL-AF9 (D544R) 6) MLL-AF9 (D546R)
2015-04-30 | E-GEOD-64365 | biostudies-arrayexpress
Project description:ASH1L and MLL1 are two histone methyltransferases that facilitate transcriptional activation during normal development. However, the roles of ASH1L and its enzymatic activity in the development of MLL-rearranged leukemias are not fully elucidated in Ash1L gene knockout animal models. In this study, we used an Ash1L conditional knockout mouse model to show that loss of ASH1L in hematopoietic progenitor cells impaired the initiation of MLL-AF9-induced leukemic transformation in vitro. Furthermore, genetic deletion of ASH1L in the MLL-AF9-transformed cells impaired the maintenance of leukemic cells in vitro and largely blocked the leukemia progression in vivo. Importantly, the loss of ASH1L function in the Ash1L-deleted cells could be rescued by wild-type but not the catalytic-dead mutant ASH1L, suggesting the enzymatic activity of ASH1L was required for its function in promoting MLL-AF9-induced leukemic transformation. At the molecular level, ASH1L enhanced the MLL-AF9 target gene expression by directly binding to the gene promoters and modifying the local histone H3K36me2 levels. Thus, our study revealed the critical functions of ASH1L in promoting the MLL-AF9-induced leukemogenesis, which provides a molecular basis for targeting ASH1L and its enzymatic activity to treat MLL-arranged leukemias.
2021-09-07 | GSE183413 | GEO
Project description:To explore oncogene addiction programs in a genetically defined leukemia context we developed an AML mouse model driven by a conditional MLL-AF9 allele together with oncogenic Ras, which enabled us to examine the consequences of MLL-AF9 inhibition in established disease. In order to produce a tightly regulated system that was easy to monitor, we constructed two retroviral vectors containing dsRed-linked MLL-AF9 under control of a tetracycline response element promoter, and KrasG12D or NrasG12D linked to the “Tet-off” tet-transactivator, which activates TRE expression in a doxycycline repressible manner. Leukemias were generated by retroviral cotransduction of both vectors into hematopoietic stem and progenitor cells, which were transplanted into syngeneic mice. Cells harboring both constructs induced aggressive myelomonocytic leukemia. Five independent primary leukemia cell lines were established from bone marrow of terminal mice. Treatment of these lines with doxycycline rapidly turned off MLL-AF9 expression, and induced terminal myeloid differentiation and complete disease remission in vivo. To identify molecular mechanisms underlying addiction to MLL-AF9, we analyzed global gene expression changes following doxycycline-induced suppression of MLL-AF9.
2011-08-05 | GSE30746 | GEO
Project description:The pathways by which oncogenes, such as MLL-AF9, initiate transformation and leukemia in humans and mice are incompletely defined. In a study of target cells and oncogene dosage, we found that Mll-AF9, when under endogenous regulatory control, efficiently transformed LSK (Lin- Sca1+ c-kit+) stem cells while committed granulocyte-monocyte progenitors (GMPs) were transformation-resistant and did not cause leukemia. Mll-AF9 was expressed at higher levels in hematopoietic stem (HSC) than GMP cells. Mll- AF9 gene dosage effects were directly shown in experiments where GMPs were efficiently transformed by the high dosage of Mll-AF9 resulting from retroviral transduction. Mll-AF9 up-regulated expression of 196 genes in both LSK and progenitor cells, but to higher levels in LSKs than in committed myeloid progenitors. Keywords: mutant hematopoietic cells
2008-02-25 | GSE10627 | GEO
Project description:To explore oncogene addiction programs in a genetically defined leukemia context we developed an AML mouse model driven by a conditional MLL-AF9 allele together with oncogenic Ras, which enabled us to examine the consequences of MLL-AF9 inhibition in established disease. In order to produce a tightly regulated system that was easy to monitor, we constructed two retroviral vectors containing dsRed-linked MLL-AF9 under control of a tetracycline response element promoter, and KrasG12D or NrasG12D linked to the “Tet-off” tet-transactivator, which activates TRE expression in a doxycycline repressible manner. Leukemias were generated by retroviral cotransduction of both vectors into hematopoietic stem and progenitor cells, which were transplanted into syngeneic mice. Cells harboring both constructs induced aggressive myelomonocytic leukemia. Five independent primary leukemia cell lines were established from bone marrow of terminal mice. Treatment of these lines with doxycycline rapidly turned off MLL-AF9 expression, and induced terminal myeloid differentiation and complete disease remission in vivo. To identify molecular mechanisms underlying addiction to MLL-AF9, we analyzed global gene expression changes following doxycycline-induced suppression of MLL-AF9. Independent primary acute myeloid leukemia lines induced by cotransduction of Tet-off MLL-AF9 together with either KrasG12D or NrasG12D were grown in culture and treated with doxycycline for 6 days to inactivate MLL-AF9 expression. In addition, primary acute myeloid leukemia lines with constitutive MLL-AF9 and KrasG12D were included to control for the effects of doxycycline. Untreated and treated cells were harvested for RNA extraction and hybridization to Affymetrix arrays.
2011-08-04 | E-GEOD-30746 | biostudies-arrayexpress
Project description:A t(9;11)(p22;q23) translocation produces the MLL-AF9 fusion protein, which is found in up to 25% of de novo AML cases in children. Despite major advances, obtaining a comprehensive under-standing of context-dependent MLL-AF9-mediated gene programs during early hematopoiesis is challenging. Here, we generated a human inducible pluripotent stem cell (hiPSC) model with a doxycycline dose-dependent MLL-AF9 expression. We exploited MLL-AF9 expression as an onco-genic hit to uncover epigenetic and transcriptomic effects on iPSC-derived hematopoietic develop-ment and the transformation into (pre-)leukemic states. In doing so, we observed a disruption in early myelomonocytic development. Accordingly, we identified gene profiles that were consistent with primary MLL-AF9 AML and uncovered high-confidence MLL-AF9-associated core genes that are faithfully represented in primary MLL-AF9 AML, including known and presently unknown factors. Using single-cell RNA-sequencing, we identified an increase of CD34 expressing early hematopoietic progenitor-like cell states as well as granulocyte-monocyte progenitor-like cells upon MLL-AF9 activation. Our system allows for careful chemically controlled and stepwise in vitro hiPSC-derived differentiation under serum-free and feeder-free conditions. For a disease that cur-rently lacks effective precision medicine, our system provides a novel entry-point into exploring po-tential novel targets for personalized therapeutic strategies.
2023-05-03 | GSE217014 | GEO